cirq.NoiseModel

Replaces operations and moments with noisy counterparts.

Used in the tutorials
Coherent vs Incoherent Error with XEB Noisy Simulation Rabi oscillation experiment

A child class must override at least one of the following three methods:

noisy_moments
noisy_moment
noisy_operation

The methods that are not overridden will be implemented in terms of the ones that are.

Simulators told to use a noise model will use these methods in order to dynamically rewrite the program they are simulating.

Methods

@classmethod
from_noise_model_like(
    noise: 'cirq.NOISE_MODEL_LIKE'
) -> 'cirq.NoiseModel'

Transforms an object into a noise model if unambiguously possible.

Args
`noise`	`None`, a `cirq.NoiseModel`, or a single qubit operation.

Returns
`cirq.NO_NOISE` when given `None`, `cirq.ConstantQubitNoiseModel(gate)` when given a single qubit gate, or the given value if it is already a `cirq.NoiseModel`.

Raises
`ValueError`	If noise is a `cirq.Gate` that acts on more than one qubit.
`TypeError`	The input is not a `cirq.NOISE_MODE_LIKE`.

is_virtual_moment(
    moment: 'cirq.Moment'
) -> bool

Returns true iff the given moment is non-empty and all of its operations are virtual.

Moments for which this method returns True should not have additional noise applied to them.

Args
`moment`	`cirq.Moment` to check for non-virtual operations.

Returns
True if "moment" is non-empty and all operations in "moment" are virtual; false otherwise.

noisy_moment(
    moment: 'cirq.Moment', system_qubits: Sequence['cirq.Qid']
) -> 'cirq.OP_TREE'

Adds noise to the operations from a moment.

Args
`moment`	The moment to add noise to.
`system_qubits`	A list of all qubits in the system.

Returns
An OP_TREE corresponding to the noisy operations for the moment.

noisy_moments(
    moments: Iterable['cirq.Moment'], system_qubits: Sequence['cirq.Qid']
) -> Sequence['cirq.OP_TREE']

Adds possibly stateful noise to a series of moments.

Args
`moments`	The moments to add noise to.
`system_qubits`	A list of all qubits in the system.

Returns
A sequence of OP_TREEs, with the k'th tree corresponding to the noisy operations for the k'th moment.

noisy_operation(
    operation: 'cirq.Operation'
) -> 'cirq.OP_TREE'

Adds noise to an individual operation.

Args
`operation`	The operation to make noisy.

Returns
An OP_TREE corresponding to the noisy operations implementing the noisy version of the given operation.